Another new guy with fire box questions

  • Some of the links on this forum allow SMF, at no cost to you, to earn a small commission when you click through and make a purchase. Let me know if you have any questions about this.
SMF is reader-supported. When you buy through links on our site, we may earn an affiliate commission.

xprmntl1

Newbie
Original poster
Nov 1, 2010
7
10
Ok, here's what i've got, a 250 gallon propane tank that someone already cut into. I'm needing to figure my firebox size but am having trouble with the calculators on here. My smoker main body is 30in diameter x 66in. long. I was planning on building my firebox 30w x 24h x 24 long. Also how big does my box to smoker opening need to be and how long should my exhaust be? Thanks!
88b41c7a_HPIM2277.jpg
 
icon_cool.gif


Well thats all sounds good to me but I bought my smoker. Can you stop into Roll Call and introduce yourself and your equipment. But then you can wait and someone will come around and give you all the info that you'll need.
 
Looks like a big project!!  Can't wait to see pix of the progress.  I've never built a SFB unit, but stick around and someone will be along to help with the calcs.  Welcome to SMF!
 
Well, went ahead and got started on the firebox yesterday at weld class, dimensions are 30w x 24 1/8 x 24 1/8. Guys at class are questioning its size, but I told them I researched the net and what I came up with is firebox should be 1/3 the size of the smoker. This thing is heavy and huge, it took 3 guys just to get it on the trailer and i'm not done with it yet! Made out of 3/8 AR plate.
fb76ede1_HPIM2279.jpg
 
Last edited:
Your firebox is plenty big, better than too small. According to the calculator you need;

17" x 8" rectangle firebox to main cook chamber opening

4, 4" rectangle firebox air inlets

A 69" stack at 4" i.d.

These #s change if you go from rectangular to circular as well as stack length depending on what size pipe you use.

You can also use square tubing as long as you have 864 cu inches of volume.
icon_smile.gif
 
ee015afd_HPIM2292.jpg


Actually I am almost finished now, just need to cut the hole for my temp. gauge and finish the other side of the trailer for my wood storage. Been pretty busy working on it on my days off. Thing cooks great, holds a good even temp even in cold temperatures!
 
Hey hey that rig of  yours there looks mighty NiCE. I like the way you positioned your firebox in there into the cooking chamber. Inside pics please, inquiring minds want to know!
PDT_Armataz_01_34.gif
 
 
c25244d0_HPIM2301.jpg


05f7b1e3_HPIM2302.jpg
e1a0d29a_HPIM2303.jpg


c3e686a9_HPIM2300.jpg


Here's the firebox to smoker damper, I made several settings to shut down heat if needed. I need to make changes to my fire grate, my cast iron ones have got too hot and bent.
 
Last edited:
For your firebox grate, how about using some of the same size angle iron you used for the riser.  Cut several pieces that will set down in your framework like this:

^^^^^^^^

Lay them in with enough of a gap between each one for adequate airflow and for ash to fall through, and just tack them in place.  Should never warp enough to matter.
 
SmokingMeatForums.com is reader supported and as an Amazon Associate, we may earn commissions from qualifying purchases.

Latest posts

Hot Threads

Clicky